Geography - Extreme Environments - Physical processes and landforms

There are three different types of desert processes; weathering, erosion and deposition.

Weathering is the breaking up of rocks in the place they are found. Weathering is carried out by the weather, plants and animals and chemicals. Types of weathering;

- Insolation weathering (also known as exfoliation) - This is caused by the sun causing minerals in the rock to heat up and cool down at different rates putting strain on the rock and causing it to falll off

Freeze - thaw weathering - Because of the diurnal range the deserts are freezing at night. When the temperatures fall to freezing or below, the moisture that has collected in the rocks during the day freezes and expands by 10%. It then causes the rock to split and break away.

Salt weathering - As the desert temperatures are high, any water collect in rocks will rapidly evaporate, leaving behind salt crystals. As these crystals grow and expand thy force the rock apart causing it to break.

The next type of physical processes in the desert is erosion. Erosion is the removal of material that has been loosened by weathering. In deserts, erosion is mainly caused by the wind, but sometimes by running water. e.g. flash floods. These are erosion processes:

Deflation - This is the gradual removal of sand to leave a flat or hollow surface.

Abrasion - This is the sandblasting effect of sand particles carried in the wind. It can sometimes erode the rock into unusual shapes.

Deposition is another type of physical process in the desert. It is sometimes classed as erosion…